Circumference vs. Diameter

B
10 ft.
10 ft.
A
20 ft.
1. Find the distance a skateboarder travels from the top of one ramp to the top of the other. (Hint: What
is the length of arc AB?)
2. Another launch ramp is formed by 2 arcs, each with a central angle of 60 degrees and a radius of 10
ft. Find the length from the top of one ramp to the top of the other. (Hint: What fractional part of the
circle is each arc?)
3. A third ramp is a straight ramp 4 ft. high and 10 ft. long with a flat space of 20 ft. Find the length of
the ramps from point P to point R. (Hint: Use the Pythagorean Theorem)
P
X
X
R
4 ft.
4 ft.
10 ft.
20 ft. 10 ft.
Sample assessment
· A school track is formed by 2 straight segments joined by 2 half circles. Each segment is l long and
each half-circle diameter is d in length. Write a formula for finding the distance, D, around the track.
Follow-up/extension
Soda Straws
How many straws full of pineapple juice can be taken from a 46-fl.-oz. can of juice that is filled to the
top?
1. Measure to find the following:
Diameter of the can: _________
Height of the can: ___________
Diameter of the straw: _________ Length of the straw: ___________
2. Explain how you determined your answers.